Structure of a closed-chain horizontal lower limb rehabilitation robot

Abstract

The present invention relates to the technical field of medical rehabilitation devices, and particularly to a closed-chain horizontal lower limb rehabilitation robot structure, which includes a frame, a driving mechanism, and a sagittal plane rehabilitation mechanism. The sagittal plane rehabilitation mechanism is a movable Z-shaped mechanism, and the human thigh, calf, and foot are respectively fixed on the sagittal plane rehabilitation mechanism. The driving mechanism is arranged on the frame and connected to the sagittal plane rehabilitation mechanism. The sagittal plane rehabilitation mechanism rotates under the action of the driving mechanism to realize the active and passive movements of the hip joint and the knee joint around the human coronal axis, and complete the lower limb rehabilitation training. By adopting a double-closed-loop closed-chain structure, under the action of the driving mechanism, through innovative configuration design and an adaptive / impedance control system, the active and passive movements of the hip joint and the knee joint around the human coronal axis, and the active and passive movements of the ankle joint around the human coronal axis and the vertical axis are realized, ensuring the safety and stability of the rehabilitation process and completing the lower limb rehabilitation training.

Description

Technical Field

[0001] The present invention relates to the technical field of medical rehabilitation devices, and particularly to a structure of a closed-chain horizontal lower limb rehabilitation robot. Background Art

[0002] Nowadays, the aging situation in our country is severe. The elasticity and toughness of the bones of the elderly aged 60 and above will gradually decrease with age. In addition, it will also cause diseases such as hypertension, cerebral thrombosis, and stroke, all of which will result in lower limb movement disorders. Traditional rehabilitation methods have problems such as a small number of rehabilitation physicians, high rehabilitation costs, and long rehabilitation cycles. Lower limb rehabilitation robots are intelligent bionic electromechanical devices that span many disciplines such as rehabilitation medicine, mechanics, robotics, computer science, control science, and artificial intelligence.

[0003] Lower limb rehabilitation robots can meet the needs of patients with different requirements or different rehabilitation stages of the same patient by adjusting the movement trajectory and providing different training modes, and can also reduce the burden on medical staff. Therefore, lower limb rehabilitation robots can be divided into suspension weight-reducing type, independent wearable type, sitting and lying type, etc. according to their structures.

[0004] Suspension weight-reducing rehabilitation robots can detect, evaluate, and guide the training status of patients, have strong functional adaptability, and can provide corresponding gait patterns and solutions according to different body types, but their dynamic models are relatively complex and the control difficulty is relatively large; independent wearable rehabilitation robots can provide energy through the power supply in the backpack and drive the lower limb assistive device at the joint to assist the patient to stand and walk, but crutches are needed to stabilize the patient's balance, and this structure is more applied in the later stage of the patient's rehabilitation.

[0005] Therefore, in view of the training and safety needs in the early stage of patient lower limb rehabilitation, we designed a new structure of a closed-chain horizontal lower limb rehabilitation robot. Summary of the Invention

[0006] To overcome the defects of the prior art, the purpose of the present invention is to provide a structure of a closed-chain horizontal lower limb rehabilitation robot, which has four different training modes, stable movement, and can meet the requirements of the rehabilitation training of the human lower limb joints in the sagittal plane.

[0007] For this purpose, the present invention proposes a structure of a closed-chain horizontal lower limb rehabilitation robot, including a frame assembly, a driving mechanism, and a sagittal plane rehabilitation mechanism. The sagittal plane rehabilitation mechanism is a movable Z-shaped mechanism. The human thigh, calf, and foot are respectively fixed on the sagittal plane rehabilitation mechanism. The driving mechanism is arranged on the frame assembly and connected to the sagittal plane rehabilitation mechanism. The sagittal plane rehabilitation mechanism rotates under the action of the driving mechanism to realize the active and passive movement of the hip joint and knee joint around the human coronal axis, and complete the lower limb rehabilitation training.

[0008] The sagittal plane rehabilitation mechanism includes a thigh rod, a calf rod, a thigh leg support, and a calf leg support; the drive mechanism includes a first servo motor, a first power arm, a first power arm pull rod, a second servo motor, a second power arm, and a second power arm pull rod; among them, the thigh rod, the calf rod, the second power arm pull rod, and the second power arm form a double crank mechanism. The second servo motor drives the second power arm to swing, thereby driving the calf rod to swing relative to the thigh rod to achieve the active and passive movement of the knee joint; the frame assembly, the thigh rod, the first power arm, and the first power arm pull rod also form a double crank mechanism. The first power arm drives the first power arm pull rod to swing, thereby driving the thigh rod to swing relative to the frame assembly to achieve the active and passive movement of the hip joint.

[0009] Furthermore, the thigh rod includes a thigh rod fixed part and a thigh rod sliding part, which are slidably connected; at the same time, the second power arm pull rod also includes a pull rod fixed part and a pull rod sliding part, so that the working length of the thigh rod can be adjusted and can match the length of the human thigh.

[0010] Furthermore, a thigh telescopic mechanism is provided on one side of the thigh rod. One end of the thigh telescopic mechanism is connected to the second power arm, and the other end of the thigh telescopic mechanism is respectively connected to the thigh rod sliding part and the pull rod sliding part.

[0011] Furthermore, the thigh telescopic mechanism includes a parallel lifting mechanism, a manual push rod, a telescopic rod sleeve, and a hand-tightening screw; the manual push rod is slidably connected to the telescopic rod sleeve, and the two are locked by the hand-tightening screw; the middle of the parallel lifting mechanism is hinged to the manual push rod, and the two ends of the parallel lifting mechanism are respectively hinged to the thigh rod sliding part and the pull rod sliding part.

[0012] Furthermore, both the thigh rod sliding part and the pull rod sliding part include a piston cylinder and a sliding piston. The parallel lifting mechanism is connected to the piston cylinder through a non-through hinge, and a thrust ball bearing is provided between the parallel lifting mechanism and the piston cylinder.

[0013] Furthermore, a calf telescopic mechanism is provided on the calf rod. A foot pedal is installed on the slider of the calf telescopic mechanism, and the working length of the calf rod is adjusted by adjusting the position of the foot pedal.

[0014] Furthermore, the frame assembly includes a motor end frame, a locking end frame, and a frame connecting piece. The first servo motor and the second servo motor are respectively connected to the motor end frame through mounting flanges. The two ends of the first power arm and the second power arm are respectively rotatably connected to the motor end frame and the locking end frame through deep groove ball bearings.

[0015] Furthermore, hexagonal key shafts are respectively provided at the outer ends of the first power arm and the second power arm. Two locking flanges are provided on the outside of the locking end frame. The locking flanges are connected to the hexagonal key shafts, and a thrust ball bearing is provided between the locking flanges and the locking end frame, so that the locking flanges can rotate with the power arm.

[0016] Furthermore, the frame assembly further includes a fixing fixture, which is respectively connected to the motor end frame and the locking end frame, and is used for installing and fixing the entire lower limb rehabilitation robot mechanism.

[0017] The closed-chain horizontal lower limb rehabilitation robot structure provided by the present invention can achieve four rehabilitation training modes: normal gait movement, knee hugging movement, independent hip joint movement, and independent knee joint movement by setting a sagittal plane rehabilitation mechanism with a thigh rod and a calf rod, locking the angles in pairs, and then driving through a driving mechanism; adopting a double-closed-loop closed-chain structure to improve the stability and safety during the movement of the driving mechanism and improve the movement accuracy; under the action of the driving mechanism, through innovative configuration design and an adaptive / impedance control system, realize the active and passive movements of the hip joint and knee joint around the human coronal axis, and the active and passive movements of the ankle joint around the human coronal axis and vertical axis, ensuring the safety and stability of the rehabilitation process and completing the lower limb rehabilitation training.

[0018] In addition to the purposes, features, and advantages described above, the present invention has other purposes, features, and advantages. The following will refer to the drawings to further elaborate on the present invention in detail. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The specification drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0020] Figure 1 is the structural schematic diagram of the closed-chain horizontal lower limb rehabilitation robot structure of the present invention Figure 1 ;

[0021] Figure 2 is the structural schematic diagram of the closed-chain horizontal lower limb rehabilitation robot structure of the present invention Figure 2 ;

[0022] Figure 3 is the structural schematic diagram of the thigh telescopic mechanism in the closed-chain horizontal lower limb rehabilitation robot structure of the present invention;

[0023] Figure 4 is the cross-sectional view of the parallel lifting mechanism in the closed-chain horizontal lower limb rehabilitation robot structure of the present invention;

[0024] Figure 5 is the schematic diagram of the calf telescopic mechanism in the closed-chain horizontal lower limb rehabilitation robot structure of the present invention;

[0025] Figure 6 is the cross-sectional view of the structure at the first servo motor in the closed-chain horizontal lower limb rehabilitation robot structure of the present invention;

[0026] Figure 7Cross-sectional view of the connection mode between the first power arm and the first power arm pull rod in the rehabilitation robot structure of the present invention;

[0027] Figure 8 Cross-sectional view of the connection mode between the second power arm and the second power arm pull rod in the rehabilitation robot structure of the present invention.

[0028] Description of the reference numerals in the drawings

[0029] 1. First servo; 2. First power arm; 3. First power arm pull rod; 4. Second servo; 5. Second power arm; 6. Second power arm pull rod; 6-A. Pull rod fixing part; 6-B. Pull rod sliding part; 7. Mounting flange; 8. Thigh rod; 8-A. Thigh rod fixing part; 8-B. Thigh rod sliding part; 9. Calf rod; 10. Thigh leg support; 11. Calf leg support; 12. Footrest; 13. Thigh telescopic mechanism; 14. Calf telescopic mechanism; 15. Motor end frame; 16. Frame connecting piece; 17. Locking end frame; 18. Fixed clamp; 19. Locking flange; 20. Manual push rod; 21. Hand-tightening screw; 22. Telescopic rod sleeve; 23. Parallel lifting mechanism; 24. Mounting hinge; 25. Stepper motor; 26. Slide block; 27. Track; 28. Linear slide rail; 29. Deep groove ball bearing; 30. Thrust ball bearing; 31. Hexagonal key shaft; 32. Countersunk head screw; 33. Set screw; 34. Hinge locking device; 35. Non-through hinge; 36. Sliding piston. Detailed implementation manners

[0030] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0031] As Figures 1 to 8 shown, the closed-chain horizontal lower limb rehabilitation robot structure of the present invention includes a frame assembly, a driving mechanism, a sagittal plane rehabilitation mechanism and a length adjustment assembly. One end of the driving mechanism is fixedly installed on the frame assembly, and the other end is connected to the sagittal plane rehabilitation mechanism. The human leg is fixed on the sagittal plane rehabilitation mechanism. Under the action of the driving mechanism, the hip joint and the knee joint perform active and passive movements around the human coronal axis, and the ankle joint performs active and passive movements around the human coronal axis and the vertical axis, completing the lower limb rehabilitation training.

[0032] Specifically, as Figures 1 to 2As shown in the figure, the frame assembly includes a motor-end frame 15, a locking-end frame 17, and a frame connecting member 16; the driving mechanism includes a first servo 1, a first power arm 2, a first power arm pull rod 3, a second servo 4, a second power arm 5, and a second power arm pull rod 6; the first servo 1 is fixedly connected to the motor-end frame 15 through a mounting flange 7, and the output shaft of the first servo 1 is coaxially connected to the first power arm 2 through the output end of the mounting flange 7; a deep groove ball bearing 29 is provided at the connection between the first power arm 2 and the frame to reduce friction during operation; one end of the first power arm pull rod 3 is hinged to the first power arm 2, and the other end is fixed to the sagittal plane rehabilitation mechanism; the second servo 4 and the second power arm 5 are connected to the frame assembly using the same structure.

[0033] As Figures 3 to 4 shown, the sagittal plane rehabilitation mechanism includes a thigh rod 8, a calf rod 9, a thigh leg support 10, a calf leg support 11, and a footrest 12; the length adjustment assembly includes a thigh telescoping mechanism 13 and a calf telescoping mechanism 14; its function is to achieve rehabilitation training of the main joints of the human lower limbs in the sagittal plane under the action of the driving mechanism.

[0034] Among them, the thigh rod 8, the calf rod 9, the second power arm pull rod 6, and the second power arm 5 form a double crank mechanism. The second servo 4 drives the second power arm 5 to swing, thereby driving the calf rod 9 to swing relative to the thigh rod 8 to achieve the active and passive movement of the knee joint; the frame assembly, the thigh rod 8, the first power arm 2, and the first power arm pull rod 3 also form a double crank mechanism. The first power arm 2 drives the first power arm pull rod 3 to swing, thereby driving the thigh rod 8 to swing relative to the frame assembly to achieve the active and passive movement of the hip joint.

[0035] The thigh rod 8 is divided into a thigh rod fixed part 8-A and a thigh rod sliding part 8-B. At the same time, the second power arm pull rod 6 also includes a pull rod fixed part 6-A and a pull rod sliding part 6-B. The thigh rod sliding part 8-B and the pull rod sliding part 6-B are connected to the thigh telescoping mechanism 13; so that the working length of the thigh rod 8 can be adjusted and can match the length of the human thigh.

[0036] Among them, the thigh telescoping mechanism 13 includes a central telescoping mechanism and a parallel lifting mechanism 23. The central telescoping mechanism includes a manual push rod 20, a telescopic rod sleeve 22, and a hand-tightening screw 21. The manual push rod 20 is slidably connected to the telescopic rod sleeve 22, and the two are locked by the hand-tightening screw 21; the telescopic rod sleeve 22 is fixed to the middle position of the second power arm 5 through a mounting hinge 24 for adjusting the lengths of the second power arm pull rod sliding part 6-B and the thigh rod sliding part 8-B, thereby adjusting the working length of the thigh rod during the rehabilitation training process.

[0037] Both ends of the parallel lifting mechanism 23 are respectively hinged to the sliding part 8-B of the thigh rod and the second power arm pull rod 6-B. Among them, since a sliding piston 36 is designed inside the sliding part 8-B of the thigh rod and the second power arm pull rod 6-B, and the outside is a piston cylinder, a non-through hinge 35 is provided at the sliding part 8-B of the thigh rod and the second power arm pull rod 6-B. The non-through hinge 35 is connected to the parallel lifting mechanism 23. At the non-through hinge 35, the parallel lifting mechanism 23 is axially locked through the internal thread, and is fixed by the rigidity of the rod and the embedded boss. To minimize the plane contact friction, a thrust ball bearing 30 is embedded between the rods.

[0038] As Figure 5 shown, a calf telescoping mechanism 14 is provided on the calf rod 9. The calf telescoping mechanism 14 includes a stepping motor 25, a slider 26, a track 27, and a linear slide rail 28. The foot pedal 12 is fixed on the slider 26. Among them, the linear slide rail 28 adopts a ball screw guide rail and can achieve self-locking. By the action of the stepping motor 25, the position of the foot pedal 12 is adjusted to adjust the length of the calf.

[0039] As Figure 6 shown, the output shaft of the first servo motor 1 is coaxial with the output end of the mounting flange 7 and is connected to the first power arm 2 to transmit power to the first power arm 2. A deep groove ball bearing 29 is provided at the connection between the first power arm 2 and the frame to reduce the friction during operation. A hexagonal key shaft 31 is provided at the locking flange 19 end of the first power arm 2. The hexagonal key shaft 31 is connected to the locking flange 19 to drive the locking flange 19 to rotate. By aligning the hole positions of the frame and the locking flange 19, the purpose of restricting the rotation of the first power arm 2 can be achieved.

[0040] As Figure 7 shown, a deep groove ball bearing 29 is provided at the sandwich between the first power arm pull rod 3 and the first power arm 2 to reduce the rotational friction, and at the same time it is convenient for installation and disassembly. The axial position inside the double-layer rod is locked by a countersunk head screw 32.

[0041] As Figure 8 shown, a hinge locking device 34 is provided between the second power arm 5 and the second power arm pull rod 6 to axially restrict the pull rod and can install another connecting rod at this hinge as conveniently as possible. To prevent the hinge locking device 34 from loosening and falling off, a set screw 33 is provided between the hinge locking device 34 and the second power arm pull rod 6. Among them, the set screw 33 extends radially along the hinge locking device 34. To reduce the rotational resistance, deep groove ball bearings 29 are provided between the surfaces to reduce the rotational friction resistance.

[0042] Among them, the entire rehabilitation mechanism is stacked by five layers of rods. The first driving arm 2, the second driving arm pull rod 6, and the thigh rod 8 are designed as single-layer rods, while the first driving arm pull rod 3, the second driving arm 5, and the calf rod 9 are designed as double-layer rods. The sandwich design between the calf rod 9 and the thigh rod 8 is the same as that between the first driving arm pull rod 3 and the first driving arm 2.

[0043] The second driving arm is a double-layer rod structure, and a thrust ball bearing 30 and a small shaft shoulder are designed to reduce the friction between surfaces. By locking the follower rod of the second driving arm 5 with the locking flange 19, the rotation of the second driving arm 5 can be restricted. The first driving arm 2, the second driving arm 5, and the frame can achieve four rehabilitation training modes of normal gait movement, knee hugging movement, independent hip joint movement, and independent knee joint movement by locking the angles between them pairwise.

[0044] In this solution, the lower limb rehabilitation robot further includes a fixing fixture 18, which is respectively connected to the motor end frame 15 and the locking end frame 17. The fixing fixture 18 can be clamped on a certain fixed plate member to install and fix the entire mechanism.

[0045] It should be noted that different structures can also be used to achieve the telescoping of the thigh and calf. The central telescoping mechanism in the thigh telescoping mechanism 13 can be replaced by mechanisms such as cylinders, electric telescopic rods, and servo slides. Similarly, the calf telescoping mechanism 14 can also be replaced by mechanisms such as cylinders, manual telescopic rods, and servo slides.

[0046] The working principle and process of the closed-chain horizontal lower limb rehabilitation robot structure of the present invention are briefly described below with reference to the accompanying drawings.

[0047] When the rehabilitation robot is working, by locking the angles between the first driving arm 2, the second driving arm 5, and the frame assembly pairwise, four rehabilitation training modes of normal gait training, knee hugging training, independent hip joint training, and independent knee joint training can be achieved. The specific implementation methods are as follows:

[0048] Within the movement range of the mechanism, according to the normal gait of the human body, a given end trajectory is set, and by controlling the swing angles of the first servo motor and the second servo motor, normal two-degree-of-freedom gait training is achieved;

[0049] When the first driving arm 2 moves normally, the second driving arm 5 is locked, so that the mechanism operates with a single degree of freedom in the sagittal plane to achieve knee hugging training;

[0050] When the second driving arm 5 moves normally, the first driving arm 2 is locked, so that the mechanism operates with a single degree of freedom in the sagittal plane to achieve independent knee joint training;

[0051] Lock the angle between the first power arm 2 and the second power arm 5 at 90°, so that the mechanism operates with a single degree of freedom in the sagittal plane to achieve independent hip joint training.

[0052] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A structure of a closed-chain horizontal lower limb rehabilitation robot, characterized in that, It includes a frame assembly, a driving mechanism and a sagittal plane rehabilitation mechanism. The sagittal plane rehabilitation mechanism is a movable Z-shaped mechanism. The thigh, calf and foot of the human body are respectively fixed on the sagittal plane rehabilitation mechanism. The driving mechanism is arranged on the frame assembly and connected to the sagittal plane rehabilitation mechanism. The sagittal plane rehabilitation mechanism rotates under the action of the driving mechanism to realize the active and passive movement of the hip joint and knee joint around the human body's coronal axis, and complete the lower limb rehabilitation training; The sagittal plane rehabilitation mechanism includes a thigh rod (8), a calf rod (9), a thigh leg support (10) and a calf leg support (11); the driving mechanism includes a first servo motor (1), a first power arm (2), a first power arm pull rod (3), a second servo motor (4), a second power arm (5) and a second power arm pull rod (6); Among them, the thigh rod (8), the calf rod (9), the second power arm pull rod (6) and the second power arm (5) form a double crank mechanism. The second servo motor (4) drives the second power arm (5) to swing, and then drives the calf rod (9) to swing relative to the thigh rod (8) to realize the active and passive movement of the knee joint; The frame assembly, the thigh rod (8), the first power arm (2) and the first power arm pull rod (3) also form a double crank mechanism. The first power arm (2) drives the first power arm pull rod (3) to swing, and then drives the thigh rod (8) to swing relative to the frame assembly to realize the active and passive movement of the hip joint; The thigh rod (8) includes a thigh rod fixing part and a thigh rod sliding part, and the two are slidably connected; at the same time, the second power arm pull rod (6) also includes a pull rod fixing part and a pull rod sliding part, so that the working length of the thigh rod (8) can be adjusted and can match the length of the human thigh; A thigh telescoping mechanism (13) is provided on one side of the thigh rod (8). One end of the thigh telescoping mechanism (13) is connected to the second power arm (5), and the other end of the thigh telescoping mechanism (13) is respectively connected to the thigh rod sliding part and the pull rod sliding part.

2. The structure of the closed-chain horizontal lower limb rehabilitation robot according to claim 1, wherein The thigh telescoping mechanism (13) includes a parallel lifting mechanism (23), a manual push rod (20), a telescopic rod sleeve (22) and a hand-tightening screw (21); the manual push rod (20) is slidably connected to the telescopic rod sleeve (22), and the two are locked by the hand-tightening screw (21); the middle part of the parallel lifting mechanism (23) is hinged to the manual push rod (20), and the two ends of the parallel lifting mechanism (23) are respectively hinged to the thigh rod sliding part and the pull rod sliding part.

3. The structure of the closed-chain horizontal lower limb rehabilitation robot according to claim 2, characterized in that, Both the thigh rod sliding part and the pull rod sliding part include a piston cylinder and a sliding piston (36). The parallel lifting mechanism (23) is connected to the piston cylinder through a non-through hinge (35), and a thrust ball bearing (30) is provided between the parallel lifting mechanism (23) and the piston cylinder.

4. The structure of the closed-chain horizontal lower limb rehabilitation robot according to claim 1, wherein, A calf telescopic mechanism (14) is provided on the calf rod (9), and a foot pedal (12) is installed on a slider (26) of the calf telescopic mechanism (14). The working length of the calf rod (9) is adjusted by adjusting the position of the foot pedal (12).

5. The structure of the closed-chain horizontal lower limb rehabilitation robot according to claim 1, wherein, The frame assembly includes a motor end frame (15), a locking end frame (17), and a frame connecting member (16). The first servo (1) and the second servo (4) are respectively connected to the motor end frame (15) through mounting flanges (7). Both ends of the first power arm (2) and the second power arm (5) are rotatably connected to the motor end frame (15) and the locking end frame (17) respectively through deep groove ball bearings (29).

6. The structure of the closed-chain horizontal lower limb rehabilitation robot according to claim 5, wherein, Hexagonal key shafts (31) are respectively provided at the outer ends of the first power arm (2) and the second power arm (5). Two locking flanges (19) are provided on the outside of the locking end frame (17). The locking flanges (19) are connected to the hexagonal key shafts (31), and a thrust ball bearing (30) is provided between the locking flanges (19) and the locking end frame (17) so that the locking flanges (19) can rotate together with the power arms.

7. The structure of the closed-chain horizontal lower limb rehabilitation robot according to claim 5, characterized in that, The frame assembly further includes a fixing fixture (18). The fixing fixture (18) is respectively connected to the motor end frame (15) and the locking end frame (17) and is used for installing and fixing the entire lower limb rehabilitation robot mechanism.

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